Electron discharge device



Oct. l l, 1932.

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s. RUEN LECTRON DISCHARGE DEVICE Filed Jan. 22, 1929 woemtoz SAMUEL RUBEN Patented Oct. 11, 1932 UNITED STATES PATENT OFFICE SAMUEL RUBEN, OF NEW YORK, N. Y., ASSIGNOR, BY MESNE ASSIGNMENTS, TO RUBEN TUBE COMPANY, OF ENGLEWOOD, NEW JERSEY, A CORPORATION OF DELAWARE ELEc'rEoN DISCHARGE. DEVICE Application filed January 22, 1929. Serial No. 334,346.

This invention relates to an electron discharge device and more particularly it relates to a vacuum discharge device in which the electron stream is controlled by an electromagnetic field.

The use of a magnetic field to control an electron discharge is known to the prior art; but by those means the control is limited and various other restrictions prevail. By my invention the arrangement and combination of elements and the method of their application, a means is provided by which the limitations referred to are eliminated and an electron stream response is obtained that is sensitive to magnetic lields of low intensity.

The fundamental requirements for such sensitive response are internal armature plates providing a constricted electron stream path and an electrostatically shielded plate element.

For a better understanding of the invention reference is made to the accompanying drawing showing an embodiment thereof, in which Fig. l illustrates an electron discharge tube having in addition to the usual elements, internal magnetic armature plates, Fig. 2 showing in section a plan view of the tube elements taken on the line of 2 2 of Fig. l and Fig. 3 is dia-grammatically illustrative of the device with the external magnetic fields, arranged in an electric circuit to which the invention is applicable.

The arrangement of the cathode, grid and plate is such that the plate is electrostatically shielded by the grid; also by this arrangement the impedance of the plate circuit is reduced. In addition, within the tube, highly evacuated to obtain a pure electron discharge, are two magnetically conductive plates separated' by a narrow gap.

Referring more particularly to Fig. 1, E represents a glass envelope containing in a high vacuum, l'ilamentary cathode l, and grid 3, which electrostatically shields anode 4.-. At 5 are arranged armature plates of amagnetic material, such as nickel-steel or pure iron, separated from each other by narrow gap 5a. Lilie numerals are employed in Figs. 2 and 3 to represent corresponding elements. In Fig. 3, 6 represents two external magnetic armatures andin the circuits B is a source of potential for energizing cathode l, B1, asource of potential for accelerating the electron .disl charge to the .grid and' plate elements. At M is a micro-ammeter to indicate the plate cur-v rent and at 7 is a bar of magnetic material,v to be tested for its permeability.v

In the operation of the magnetic tube as shown; by the arrangement of Fig. 3, when 'the filament, grid and plate` are'sufhciently energized there is an electron flow from the filament through gap 5c to the grid 3 and plate 4, the meter M, indicating the plate current. The armatures 5 lare magnetized by the external magnetic iield and the electron stream is diverted from its path to a degree determined by the intensity of the field, the space charge being increased, with a corresponding reduction lof the plate current. This current is reduced to zero when a field of lsuflicient intensity is applied. By the use of the external magnetic armatures 6, armatures 5, are energized thereby.

In Fig. 3 the external armatures 6, are bridged by a bar of magnetic material 7, which aords a path of lower reluctancepfor ask the external magnetic field and effects a ren ductionl of the plate current, the reduction varying with the permeability of the bar.

By the use of the shielding grid 3, the plate current change for a given magnetic field variation in the armature is many timesV increased, thus producing extreme sensitivity of response in the pla-te current to lield intensities of low values. This effect is comparative with that from an electrostatically operated shield grid tube in which relatively large plate current changes occur with a low potential on the control grid.

This device is applicable to many uses such as magnetic compass, motion indicator, audiofrequency amplifier, etc.

Vha-t I claim is: y

v 1. An electron device comprising, in combination, an evacuated envelope, a cathode, a grid, an electrically shielded anode and magnetic armatures,the armatures being located in a plane between the cathode and anode and spaced apa-rt by a gap between the cathode and anode. 1

2 f ,l l 1,882,449

k2. An electron device comprising, in combination, an evacuated envelope, a cathode, a

grid, an electrically shielded anode and magnetic armature plates the plates being located `l, in a plane and spaced apart by a gap between the cathode and anode, and means for magnetically .energizing said armatures.

3. An electron device comprising, in com! bination, an evacuated envelope, a cathode, a

' 10 grid, an electrically shielded anode and magnetic armature plates, said plates being located in a plane and spaced apart by a gap between the cathode to the anode, and externally mounted magnetic armatures.

4. An electron device comprising, in combination, an evacuated envelope, a cathode, a grid, an anode, the anode being electrically vshielded by the grid and magnetic armatures, said armatures being located in a plane be- V tween the cathode and the anode and spaced apart bya gap between the cathode to the anode, and magnetic armatures mounted eX- ternally of the envelope. v y

In testimony whereof, I, SAMUEL RUBEN, have signed my name to this specilication this 21st day of January, 1929.

SAMUEL RUBEN. 

